Submersible pool heater

ABSTRACT

A pool heater is disclosed that is adapted to be partially submersible in the water contained in the pool. The pool heater comprises a vent assembly, which is adapted to be supported above the pool water level, and a duct assembly, which is adapted to be submersed below the pool water level. The vent assembly comprises a vented outer housing having an exhaust stack located therein. The top cover plate of the outer housing includes an aperture formed therein. The exhaust stack terminates slightly below the aperture to enable cool inlet air to be drawn therethrough cooling the outer housing surrounding the stack. The duct assembly forms a U-shaped configuration having an inlet duct forming one of the legs. A combustion chamber is formed at the bottom of the U-shaped configuration, while the other leg of the U-shaped configuration forms heat exchange conduits. Radiant plates are located within the combustion chamber which function to feed back radiant energy into the burning air fuel thereby expediting the combustion. The heat exchange conduits are formed in a zigzag configuration for providing a turbulent flow for the combustion exhaust. An aquastat is positioned adjacent the upper end of the heat exchange conduits for sensing the temperature of the water in the vicinity thereof.

United 'States- Patent 11 Ramey [111 3,824,986 [4 1 July 23,1974

SUBMERSIBLE POOL HEATER Robert M. Ramey, North Hollywood, Calif.

Assignee: Teledyne, Inc., Los Angeles, Calif.

Filed: Jan. 17,1972

Appl. No.: 218,421

Inventor:

US. Cl. 126/360, 432/247 Int. Cl. F2411 1/20 Field of Search 126/91 A, 360; 98/58;

[56] References Cited UNITED STATES PATENTS 11/1891 Goss 432/247 X 5/1950 Turner.. 165/177 X 9/1966 Stapleton. 126/360 R 12/1966 Hall 126/360 R X 9/1967 Fleming 98/58 X [57] ABSTRACT A pool heater is disclosed that is adapted to be par,-

tially submersible in the water contained in the pool. The pool heater comprises a vent assembly, which is adapted to be supported above the pool water level, and a duct assembly, which is adapted to be submersed below the pool water level. The vent assembly comprises a vented outer housing having an exhaust stack located therein. The top cover plate of the outer housing includes an aperture formed therein. The exhaust stack terminates slightly below the aperture to enable cool inlet air to be drawn therethrough cooling the outer housing surrounding the stack. The duct assembly forms a U-shaped configuration having an inlet 3 duct forming one of the legs. A combustion chamber is formed at the bottom of the U-shaped configuration, while the other leg of the U-shaped configuration forms heat exchange conduits. Radiant plates are lofor providing a turbulent flow for the combustion exhaust. An aquastat is positioned adjacent the upper end of the heat exchange conduits for sensing the temperature of the water in the vicinity thereof.

14 Claims, Drawing Figures sum 2 or 2 PAIENIEBMZSIBH 1 ISUBMERSIBLE root 'HEATE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to heating appliances and more particularly to heating appliances that are submersible within'a large container of liquid for heating the liquid directly.

heaters preventsthe combustion from occurring efficiently and cleanly and the bulk size is objectionable.

Because of this, prior art heaters cannot produce sufficient BTUs to heat the liquid in an efficient and economical manner.

Another shortcoming with the prior art heaters is that they cannot be utilized as a pool heater. This is not only for the reasons given above, but also because the structure of the heaters which remains above the water line is not safe enough to be used around children or unsuspecting adults. With the advent of the above-ground swimming pools, a need for a commercially acceptable submersible pool heater has arisen. Since conventional pool heaters are especially adapted for permanent installation, they are usually not suitable for above-ground pools. Asstated previously, none of the prior art submersible heaters are suitable for heating. swimming pools/ Another problem with prior art heaters and their utilization in pools occurs in thermostatic control areas. One way of controlling the water temperature ina pool is through the use of a commercially available device known as an aquastat. An aquastat is a pressure tube.

2 chamber. Exhaust conduits are also connected to the combustion chamber for providing heat exchange surfaces for the water to be heated. The combustion chamber also includes radiant plates located within the combustion chamber for emitting radiant energy to the interior thereof. These radiant plates function to feed back radiant energy into the combustion chamber for aiding the combustion process.

Another feature of the present invention is that the heat exchange conduits are formed into a zigzag configuration to create a turbulent flow for the exhaust in order to enhance the heat transfer characteristics.

Still another feature of the present invention is that a flue collection chamber is provided within the vented housing for exhausting the products of combustion.

- The flue collection chamber exhaust port terminates that is temperature sensitive to control pressure actuated servo motors for turningthe heater on and off. The aquastat is usually immersed directly in the pool to directly sense the temperature of the water. The shortcoming with such a device is that itoperates' in a 6.

range. For example, if the aquastat is set to actuate when the water temperature is 80, it will'not turnoff the heater until the water temperature reaches 86. Such a large water temperature change is undesirable for many reasons. When the water is raised to that temperature, heat losses are accelerated. Moreover, such abrupt changes are not desirable because of the discomfort involved. In the'above example, 80 would be too cold for many pople while 86 would be too warm- However, these conditions had to be accepted because if the shut off temperature were lowered, the turn on temperature would be lowered an equal amount.

SUMMARY OF THE INVENTION The presentinvention obviates the above-mentioned shortcomings by providinga submersible pool heater that is especially adapted to operate in above-ground pools in a clean and efficient manner.

In its broadest aspect, the invention comprises a, vented housing for admitting air into a combustion below an aperture formed in the top cover plate to enable cooling air taken in at the bottom of the housing to be drawn therethrough.

A further feature of the present invention is that an aquastat is provided'to be positioned adjacent the upper ends-of the two heat exchange conduitsl The primary advantage of the present invention is that the radiant feed back provided by the radiant plates'within the combustion chamber causes more complete'and efficient combustion than heretofore possible in combustion chambers of comparable volumn.

Another importantadvantage of the present invention is that the zigzagging heat exchange ducts increases the turbulence of the heat flow to substantially enhance the heattransfer characteristics of the heat exchange ducts.

Still another important advantage of the present invention is that the novel vent assembly construction enables the exhaust stack and flue gases to be sufficiently vided while still using a conventional aquastat.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connectionjwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1. is a perspective view of a submersible pool heater of the present invention;

FIG. 2 is a fragmentary perspective view of the upper portion of the pool heater with the back panel of the vent assembly broken away to showthe interior thereof; a

FIG. 3 is a partial cross sectional view of the pool and heater taken substantially along lines 3-3 of FIG. 2;

FIG. 4 is a fragmentary perspective view of the combustion chamber with the side panel broken away to show the interior thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIGS. 1 and 2 illustrate a pool heater, generally indicated by arrow 10, comprising a vent assembly 20 and a submersible duct assembly 30.

The outer housing of the vent assembly 20 is formed by foursidewalls 11 forming a hood 12. The submersible duct assembly 30 is formed in a substantially U- shaped configuration comprising three main subassemblies: an inlet conduit 40, a combustion chamber 50 and the heat exchange conduits 60.

The support assembly for the heater comprises a plurality of brackets 15 attached to a pair of angle irons 17 mounted on two rear corners formed in the rear sidewalls-:11. Each pair of brackets 15 extends outwardly and is secured to a two piece tube 19. The tube 19 is adapted to be supportedly mounted on a pole (not shown) which is positionable adjacent theside" of an above-ground pool. The desired height to which the vent assembly 20 is mounted is high enough to enable the apparatus 10' to extend over the pool in a manner that the duct assembly is substantially immersed in the water contained within the pool.

As shown in FIGS. 2 and 3, the top of the vent apparatus 20 is formed by a cover plate 21 having'a rectangular aperture 22 formed thereon. The bottom of the vent assembly 20 is formed by a ported plate 23 having a first aperture 24 communicating with the interior of the intake conduit 40. The bottom plate 23 also includes a 'pair of second apertures 25 communicating with the interior of the heat exchange conduits 60.

A dome-like stack 26 is adapted to be mounted on the plate 23 to extend over the second apertures 25. The interior of the stack 27 forms an exhaust or flue collecting chamber while the area outside the stack 26 chamber 28. The top of the stack 26 is capped with an aperture29 which extendsslightly below the aperture spaced from the outer edges of the ported plate 23 to form a peripheral'inlet 16. This inlet 16 is provided to let atmospheric air enter into the inlet chamber 28. The hood 12 is connected to the ported plate 23 with suitable brackets and'fasteners (not shown) spaced about the ported plate 23.

A trough 31 is supported within the stack 26 to extend directly beneath the aperture 29 across the entire width of the stack. The extremities of the trough 31 extend through a pair of openings 32 formed in the sidewalls of the stack 26.

As shown in FIG. 3, the inlet conduit extends to the bottom of the U-shaped duct assembly 30. An opening 41 extends across the bottom of the inlet conduit 40 toform an intake passage for the combustion chamber 50.

The combustion chamber includes a bank of gas burner nozzles 51 mounted on a manifold 52 which, in turn, extends. across the width of the intake passage 41. The manifold 52 is connected to suitable piping(not shown) for connection to a source of pressurized gas.

' 4 The gas burners 51 function to introduce jets of pressurized fuel into the combustion chamber 50.

A ceramic plate 53 is angularly mounted within the combustion chamber with respect to the direction of the burner jets. The ceramic plate 53 is supported in a spaced relationship from the outer walls 54 forming the combustion chamber housing.

A pair of radiant plates 55 are, also mounted within the combustion chamber 50. As with the ceramic plate 53, the radiant plates 55 are spaced from the outer walls 54 for insulation purposes.

The upper portion of the combustionchamber 50 is formed by a cover plate 56 having a pairof apertures 57 adapted for connection to the pair of heat exchange conduits 60.

Each of the conduits 60 is formed by a pair of wall sections 61 having a plurality of cavities 63 formed on their interior sides, and forming a saw-toothed configuration. When each pair of wall sections 61 are joined together, the cavities 63 of the respective wall sections 61 are staggered or longitudinally off set. This construction forms a pair of passageways having a'circuitous path leading from thecombustion chamber 50 and within the'louvered sidewalls '11 forms an inlet through the apertures 25 to the fluecollecting chamber 'A plurality of skirts 65 are attached to the bottom side-of the plate 23 and are adapted to extend about the periphery thereof.

Finally, an aquastat is adapted to be mounted adjacent the'upper ends of the heat exchange conduits 63.

OPERATION The installation of the pool heater 10 will be describedin connection with an above-ground pool. It

should be'note'd, however, that thepool heater 10 can also operate in convention below-ground pools.

In installing. the pool heater, a stake or pole is mounted'in the ground adjacent the side. of the pool. The tube 19 is then fixedly attached to the top of the pole to enable the brackets 15 to extend over the side of the pool and support the pool heater Never the wathe support pole would be shorter'and the heater l0 would still be supported within the pool in the position shown in FIG. 3. It should be noted that other types of support means can be provided other than those described. When installed, the water flow of the water is such that it flowspast the heater as it circulates around the pool by pool filter action or by convection adjacent to the heater. I

In operation, air is drawn into the inlet chamber 28 via the inlet 16. Because of the convection currents, a portion of the air is then drawn down the inlet conduit 40 to enter the combustion chamber 50. Upon entering the combustion chamber 50, the air mixes with the pressurized gas, ejecting from the nozzles 51, to combust within the combustion chamber 50. The combustion is directed by the nozzles 51 against the angularly supported ceramic plate 53. The plate 53 functions to redirect the combustion upwardly and create a turbulence in the passing gases in the process. The turbug lence created serves to increase the combustion efficiency. t

As the flow of combustion rises between the radiant plates 55, the heat generated within functions to heat the plates 55 to a red-hot state. In this condition, the plates 55 function to feed back infra-red rays into the area therebetween. This radiant feedback greatly increases the combustion efficiency of the combustion taking place within the combustion chamber. As a result, the combustion is more complete and the generated heat is greater.

This generated heat then rises into the heat exchange conduits to heat the cavities 63 of the sidewalls 61. Because of the zigzag path provided by the offset cavities 63, the flow through the conduits 60 is quite turbulent. This turbulence functions to increase the heat transfer occurring. The heated sidewalls 61 then function to heat the water circulating past the heater 10.

The products of combustion then are gathered in the flue collection chamber 27 via the apertures 25. The combustion products then pass out through the aperture 29 located at the top of the stack 26, and finally through the aperture 22 of the cover plate 21.

The stack 21 is located completely within the vent assembly 20. A portion of the cool air entering the in- 2 to more efficiently cool the opening 22 of the plate 21,

and (2) to provide a shield for the hot exhaust mixing with and cooling the hotgases.

The advantage of having the top of the stack recessed is that it prevents unsuspecting adults or children from gases by being able to touch the hot metal of thestack 26. As

far as the flow of hot gases is concerned, they are sufficiently cooled by the mixing inlet air so as not to burn anyone. The heat of the gases function to warn the person to pull awayhis hand before the hand is burned by the gases.;

The'skirts65 are provided toshield the portion of the heat exchange conduits 63 extending above the water line and to provide a relatively stationary portionof water.

The trough 31 is provided to trap water falling into the stack 26 and transport it out through the apertures provided than heretofore possible with such aquastats.

This phenomenon will be described by way of an example. Suppose the water adjacent the conduits 60 is 80 F. The bulb 70 senses this and turns on the heater. The water is then heated approximately to 84 F at the location of the bulb 70. However, the water in the pool is the heater is then raised to a temperature of 86. When this occurs, the aquastat senses this temperature and shuts off the heater. However, the water in the pool has only been heated to a temperature of 82.

As can be seen, even though the water adjacent the bulb 70 is heated from to 86, the mean temperature of the pool water is raised only two degrees from 80 to 82 F. As a result, the pool water temperature is kept more constant. The advantage of this is that such a variance canbe maintained while still utilizing a conventional aquastat of normal sensitivity.

As can be seen, a submersible pool heater is provided that can operate more efficiently,- and safely than heretofore possible.

It should be noted that various modifications can be made to the apparatus while still remaining within the purview of the following claims.

What is claimed is:

l. A submersible swimming pool heater for heating a quantity of water contained within a swimming pool to a predetermined water temperature comprising:

a vent assembly adapted to be mounted above the water level of the pool, the vent assembly comprising an outer housing having sidewalls forming inlet air ports, an apertured exhaust, and an exhaust duct located within the outer housing;

inlet conduit means attached to the bottom side of the vent assembly and extending downward therefrom so that it is adapted to be submersed in the water contained in the pool;

a combustion chamber connected to the inlet conduit means and operative submerged below the water g level of the pool;

means for introducing combustible fuel into the combustion chamber whereby heat can be generated when the fuel is ignited; e at least one heat exchanger conduit connected to the combustion chamber and extending upward, relatively parallel and separate from the inlet conduit, to connect with the exhaust duct, the heat exchanger providing a' tortuous flow path that is adapted to increase the heat transfer over its entire surface to the surrounding swimming pool water;

temperature sensing means for controlling the generation of heat in the combustion chamber including a sensor adapted to be submerged in the water adjacent the connection of the heat exchanger and the exhaust duct, and

baffle means extending around the heat exchanger at least downward from the vent assembly below the temperature sensor and providing a relative stationary portion of water.

2. The invention of claim 1 wherein said means for introducing fuel comprises jet nozzle means for directing jets of pressurized fuel into the combustion chamber in the direction of the means for deflecting.

3. The invention of claim 1 wherein the exhaust duct further comprises a trough positioned directly beneath the exhaust aperture for trapping any water or debris falling therein.

4. The invention of claim 3 wherein the trough extends through openings formed in the exhaust duct to enable any debris or water collected on the trough to 65 pass through the openings.

5. The invention of claim 1 wherein the heat exchanger is formed from a pair of saw-toothed shaped still only approaching 82. The water the vicinity of wall sections.

6. The inventionof claim wherein a pair of heat exchangers having relatively parallel tortuous flow paths are provided.

7. A swimming pool heater for heating a quantity of water contained within a swimming pool to a predetermined water temperature comprising:

an exhaust vent assembly having an outer housing with air ports, an apertured exhaust port and an exhaust duct connected to the outer housing;

at least one heat exchanger conduit connected at one end to the exhaust duct and extending downward from the exhaust vent assembly and adapted to have its entire outer surface surrounded by swimming pool water, the heat exchanger having a zigzag configuration to form a tortuous flow path for increasing heat transfer to the surrounding water,

a combustion chamber connected to the other end of the heat exchanger;

means for providing a combustible mixture to the combustion chamber to produce heat;

temperature sensing means for controlling the generation of heatin the combustion chamber including a sensor adapted to be'submerged in the swimming pool water adjacent the connection of the heat exchanger and the exhaust duct, and

means extending around the heat exchanger at least downward from the exhaust vent assembly below the temperature sensor for confining a relatively stationary portion of water adjacent the heat exchanger and exhaust duct connection.

8. The invention of claim 7 wherein said temperature sensing means comprises a conventional aquastat.

9. The invention of claim 7 wherein the heat exchanger is formed from a pair of saw-toothed shaped wall sections.

10. The invention of claim 7 wherein the means for confining the water includes at least a side wall extending downward around the entire periphery of the vent assembly.

11. The invention of claim 10 wherein the means for providing a combustible mixture to the combustion chamber to produce heat includes jet nozzle means for directing jets of pressurized fuel into the combustion pass through said openings. 

1. A submersible swimming pool heater for heating a quantity of water contained within a swimming pool to a predetermined water temperature comprising: a vent assembly adapted to be mounted above the water level of the pool, the vent assembly comprising an outer housing having sidewalls forming inlet air ports, an apertured exhaust, and an exhaust duct located within the outer housing; inlet conduit means attached to the bottom side of the vent assembly and extending downward therefrom so that it is adapted to be submersed in the water contained in the pool; a combustion chamber connected to the inlet conduit means and operative submerged below the water level of the pool; means for introducing combustible fuel into the combustion chamber whereby heat can be generated when the fuel is ignited; at least one heat exchanger conduit connected to the combustion chamber and extending upward, relatively parallel and separate from the inlet conduit, to conneCt with the exhaust duct, the heat exchanger providing a tortuous flow path that is adapted to increase the heat transfer over its entire surface to the surrounding swimming pool water; temperature sensing means for controlling the generation of heat in the combustion chamber including a sensor adapted to be submerged in the water adjacent the connection of the heat exchanger and the exhaust duct, and baffle means extending around the heat exchanger at least downward from the vent assembly below the temperature sensor and providing a relative stationary portion of water.
 2. The invention of claim 1 wherein said means for introducing fuel comprises jet nozzle means for directing jets of pressurized fuel into the combustion chamber in the direction of the means for deflecting.
 3. The invention of claim 1 wherein the exhaust duct further comprises a trough positioned directly beneath the exhaust aperture for trapping any water or debris falling therein.
 4. The invention of claim 3 wherein the trough extends through openings formed in the exhaust duct to enable any debris or water collected on the trough to pass through the openings.
 5. The invention of claim 1 wherein the heat exchanger is formed from a pair of saw-toothed shaped wall sections.
 6. The invention of claim 5 wherein a pair of heat exchangers having relatively parallel tortuous flow paths are provided.
 7. A swimming pool heater for heating a quantity of water contained within a swimming pool to a predetermined water temperature comprising: an exhaust vent assembly having an outer housing with air ports, an apertured exhaust port and an exhaust duct connected to the outer housing; at least one heat exchanger conduit connected at one end to the exhaust duct and extending downward from the exhaust vent assembly and adapted to have its entire outer surface surrounded by swimming pool water, the heat exchanger having a zigzag configuration to form a tortuous flow path for increasing heat transfer to the surrounding water, a combustion chamber connected to the other end of the heat exchanger; means for providing a combustible mixture to the combustion chamber to produce heat; temperature sensing means for controlling the generation of heat in the combustion chamber including a sensor adapted to be submerged in the swimming pool water adjacent the connection of the heat exchanger and the exhaust duct, and means extending around the heat exchanger at least downward from the exhaust vent assembly below the temperature sensor for confining a relatively stationary portion of water adjacent the heat exchanger and exhaust duct connection.
 8. The invention of claim 7 wherein said temperature sensing means comprises a conventional aquastat.
 9. The invention of claim 7 wherein the heat exchanger is formed from a pair of saw-toothed shaped wall sections.
 10. The invention of claim 7 wherein the means for confining the water includes at least a side wall extending downward around the entire periphery of the vent assembly.
 11. The invention of claim 10 wherein the means for providing a combustible mixture to the combustion chamber to produce heat includes jet nozzle means for directing jets of pressurized fuel into the combustion chamber.
 12. The invention of claim 11 wherein a pair of heat exchangers having relatively parallel tortuous flow paths are provided.
 13. The invention of claim 7 wherein said exhaust duct further comprises a trough positioned directly beneath the exhaust aperture for trapping any water or debris falling therein.
 14. The invention of claim 13 wherein said trough extends through openings formed in said exhaust duct to enable any debris or water collected on said trough to pass through said openings. 